Portable fan base



FIG. 1 is a perspective view of the portable fan base.

FIG. 2 is the front view of the portable fan base.

FIG. 3 is a side view of the portable fan base.

FIG. 4 is the rear view of the portable fan base.

FIG. 5 is a side view, opposite of FIG. 3, of the portable fan base.

FIG. 6 is a top plan view of the portable fan base; and,

FIG. 7 is a bottom view of the portable fan base.

The broken line showing of environmental structure in FIGS. 1-7 is forillustrative purposes only and forms no part of the claimed design.

The ornamental design for a portable fan base, as shown and described.